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Topic: Help with Berliner Weisse (Read 1345 times)

I have a Berliner Weisse fermenting and am new to the style so I need some help deciding when to rack it. It's been in primary for about 10 days. I pitched a pack of Wyeast 5335 Lactobacillus on brew day (6/8/13), let that run soloat 72F to get some souring going, then gradually cooled to 66F and pitched a smack-pack of Wyeast 1007 German Ale six days later (6/14/13). The lacto fermentation was VERY active and when I added the 1007 it really took off, too. As of last night (6/18/13) fermentation activity has subsided without any activity in the airlock for a couple days - still at 66F.

I know the lacto will keep working a while and continue souring, but I think that the 1007 is probably done. There is still a little krausen and some gooey lacto stuff on the top of the beer and it hasn't dropped very clear yet. I'm planning to keg the beer and force carbonate. Should I wait for the krausen and lacto goo to drop before I rack? Is it better to rack sooner to carry over some lacto and maybe a little 1007 to keep working? I can let the beer drop clear in the keg then push to another keg for serving later.

The OG was 1.031. I'd expect that the 1007 alone would take it to around 1.010, and that the lacto will take the gravity below that as it eats up the remaining dextrines. If it's held at around 1.010 for a couple days is that a good enough indicator that it's okay to rack?

At this point, treat it like any other beer. When the gravity is constant for a few days and it tastes finished (no diacetyl, acetaldehyde, etc.), rack it.

After the initial pH drop from lacto and the alcohol fermentation, you may gain a bit more acidity in the keg, but I wouldn't wait around for a considerable change in flavor. Berliner weisse, like any wheat beer, should be consumed relatively fresh.

If you mashed low, I would suspect primary fermentation to finish lower than 1.010, but let your hydrometer and palate tell you when the beer is finished.

With such a delicate beer and a low pH, I think its important to get the beer off the yeast as soon as primary is complete. Low pH will speed autolysis, and a lighter beer will show flaws more readily.

I just followed a similar procedure, but I had much warmer initial temperatures for the lacto. I pitched the lacto at about 90 degrees and held it there for three days. There was a typical looking fermentation and then the lacto krauesen dropped. I racked the beer off the lacto that had mostly fallen to the bottom of the carboy because I want to save it for another batch, and I pitched my yeast. The lacto took the beer from 1.056 to 1.032. Now the yeast has created another krauesen, I would expect it to get down close to 1.000, based on past experience.

I don't see how the beer can really continue to sour once the pH and alcohol get to a certain point. Brettanomyces is the one that will keep fermenting once the rest of the crew gets tired. If you are going to keg it, you won't get any more souring once you chill and carbonate it. Lacto just won't work in those conditions. I would wait a little bit to see if the krauesen falls and you get no more fermentation activity then chill and keg.

Anyway, in a couple of weeks I plan on racking again - half on sour cherries, half on raspberry puree.

I don't see how the beer can really continue to sour once the pH and alcohol get to a certain point. Brettanomyces is the one that will keep fermenting once the rest of the crew gets tired. If you are going to keg it, you won't get any more souring once you chill and carbonate it. Lacto just won't work in those conditions. I would wait a little bit to see if the krauesen falls and you get no more fermentation activity then chill and keg.

At certain ph and alcohol percentage bacteria will drop off but not all bacteria is as weak as the WL/WY lacto strains. Pedio is also used to sour some beers and will keep going right alongside brett. You don't get 10% ABV sour beers without it (e.g. Bon Chien). I know pedio isn't used in berliner weisse but even wild lacto can survive against higher ABV.

Lacto will sour at cooler temperatures but much slower than at ambient or typical beer fermentation temperatures. That's one of the ways milk goes bad in your fridge. Next time you let milk run too long in your fridge, give it a smell. You'll be surprised by how similar it smells to a berliner weisse. However, by the time the beer hits stable gravity there won't be much or any more sugars that lacto can consume (at least the WL and WY strains). Lacto can break down some complex sugars but generally not the ones left behind after sacc has eaten what it can.